How Do You Calculate Confidence Interval Of Mean?
The confidence interval of the mean is a statistical term used to describe the range of values the true mean, or average, could fall in based on your data and confidence level. The most commonly used confidence level is 95 percent, which means there is a 95 percent probability that the true mean lies within the confidence interval. To calculate the confidence interval, you need to know the mean, standard deviation, sample size and confidence level you are working with. Calculate the mean by adding all of the values in your data set and dividing by the number of values. For example, if your data set was 86, 88, 89, 91, 91, 93, 95 and 99, you would get 91.5 for the average. Calculate the standard deviation for the data set (see section 2 for detailed instructions on how to calculate the standard deviation). Determine the standard error of the mean by dividing the standard deviation by the square root of the sample size. In this example, you would divide 4.14 (the standard deviation) by t
